Liquid knockout apparatus



May 12, 1953 A. s. PARKS LIQUID xNocKoUT APPARATUS Filed March 15, 1950 5 Sheets-Sheet 2 j@ g. L/WA, A TTOHNEKS May 1.2, 1953 A, S PARKS 638,223

LIQUID KNocKoUT APPARATS Filed March l5, 1950 3 Sheets-Sheet 3 Asb/ry J. Pof/fs INVENTOR. I

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A TIORNEYJ Patented May 12, 1953 UNITED STATES PATENT OFFICE LIQUID KNOCKOUT APPARATUS Asbury S. Parks, Houston, Tex.

Application March 13, 1950, Serial No. 149,375

(Cl. 21d- 52) 11 Claims. 1

This invention relates to new and useful improvements in liquid knockout apparatus.

This application is led as an improvement on the apparatus disclosed in my co-pending applcation, Serial No. 46,598, filed August 28, 1948.

The invention relates particularly to high pressure liquid knockout apparatus wherein free Water or liquid hydrocarbons are separated from a high pressure gas or distillate. The invention will be described herein as separating water from gas or distillate but it is to be understood that it may be employed for separating any liquids.

In my co-pending application above referred to, it is pointed out that the freezing problems which are encountered in high pressure gas lines are due to the gas-water hydrates and that if removal of substantially all of the water can be successfully eifected, these diiculties are overcome. Since water must be present in a liquid state in contact with the gas in order for gashydrates to form, maintenance of the gaseous stream at a temperature above dew point conditions where no liquid water exists will prevent formation of hydrates. moved at the point of highest pressure in the system and the temperature is not thereafter further lowered to the point of further condensation no hydrates will subsequently be formed.

The apparatus disclosed in my co-pending application effectively accomplishes the required removal of water under high pressure but the particular apparatus has certain structural disadvantages. For instance, the liquid accumulating chamber is illustrated as suspended from the flow line with the controls for the apparatus be- .a

ing supported by a structural frame and it has been found that atmospheric temperature changes which cause expension and contraction of the line and of the supporting structure result in deflections of the liquid accumulating chamber or movements of the controls of the apparatus which erroneously operate said controls to cause erroneous operation of the apparatus. Also, said apparatus includes a restriction or choke in the main gas line to effect a return of the hydrocarbon liquids from the accumulating chamber back into said line and such restriction may be undesirable under certain conditions. In addition the prior apparatus has other features which although not interfering with the ultimate efficient results obtained by said apparatus, are not too desirable from an economical standpoint.

It is therefore one object of this invention to provide a liquid knockout apparatus having all of the advantages of the apparatus shown in my If the free water is reco-pending application, Serial No. 46,598, filed August 28, 1948, and in addition having certain improvements thereover which assure more ecient and reliable operation of the apparatus.

An important object of the invention is to provide a high pressure separating apparatus having improved control means for controlling the dumping or escape of the separated liquid, which and which utilizes the weight of the separated liquid as the controlling factor in actuating the liquid escape or dump Valve, whereby the liquidaccumulation vessel may be of a relatively small size and also whereby the overall construction of the unt may be made more rugged to withstand the high pressures encountered without sacrifica. ing sensitivity in operation.

the various control devices of the apparatus are suspended from the gas flow line and, in effect,

form a part thereof whereby the chamber andl controls are maintained in the same positionsl with respect to each other irrespective of expansion and contraction of the flow line as caused by atmospherictemperature changes.

A particular object is to provide an improvedv liquid knockout apparatus, of the character described, having means for returning the hydrocarbon liquid from the accumulating chamber back to the gas fiow line without the necessity of locating a restriction in said line.

A further object is to provide an -apparatus of the character described wherein the separating vessel is entirely independent of the accumulating vessel and control devices and is connected thereto by the gas ow line, whereby said flow line forms the sole support for the complete apparatus.

A still further object is to arrange the connection between the gas ow line and the liquid accumulating Vessel in a manner to cause the owing gas stream to function to automatically draw the hydrocarbon liquid back into said line from the liquid accumulating chamber; the arrangement also assuring the maintenance of a predetermined constant hydrocarbon liquid level whereby control of the apparatus is solely in accordance with the rise and fall in the level of the water in the accumulating vessel.

Other further obi ects of this invention will appear from the following description.

In the accompanying drawings which form a part of the instant specification, are to be read in conjunction therewith, and wherein an example oi the invention is shown:

Figure l is an isoinetric view, with portions in section, of a liquid knockout apparatus con structed in accordance with the invention,

Figure 24 is a elevation thereof, viewing the apparatus from the side opposite that of Figure 1,

Figure 3 is a longitudinal sectional View of the apparatus,

Figure 4 is a horizontal cross-sectional view, taken' on the line ll-Li of Figure Figure 5 is an end elevation,

Figure 6 is an enlarged sectional View of the pilot pressure control device which is actuated by deflections of the liquid accumulating vessel,

Figure 7 is a View, partly in section and partly in elevation, 'of the motor valve which controls dumping of the liquid from the liquid accumulating chamber, and

Figure 8 is a sectional View of the regulator which controls the now of a portion of the gas from the high pressure now line to the pilot sup ply line.

In the drawings, the numeral in designates a high pressure now line through which a high pressure gas stream is conducted. The line ill may extend from the well head of a high pressure gas or distillate well or may extend from any other source of high pressure iluid. The flow stream within the line lll may consist of gas, hydrocarbon liquid and water, and said stream is directed into suitable horizontal separator or scrubber il. The separator functions to `separate the gas from the free liquids in the flow stream and the separated gas ows from the separator through a down pipe i3. The pipe extends downwardly in a below the sepn arator has connection with a lateral or hori' zontal pipe section hl which is connected to a Ti5 from which an upwardly projecting pipe leg lll extends. The upper end of the leg is connected through a turn or elbow il with the flow pipe ma, which pipe forms a part of the flow line. lt will be evident that the down pipe i3. the lateral portion ill and the upstanding leg I6 actually form a downwardly directed. offset in theA now line which is formed by the pipes ill and ita.

The now stream enters the horizontal separator and the separated gas, upon leaving said separator, escapes through the offset formed by the pipes lil, it and in then passes clownstrearn through the itu.. lThe liquids which are separated within the horizontal separator or scrubber il are conducted therefrom through a conductor i8. This conductor has a vertical portion lila which has its upper end welded or otherwise secured to the shell of the separator I i. rIhe conductor also includes an elongate lateral or horizontal portion iilb which has connection with a curved conduit ill. As is clearly shown in Figure 5, the conduit has an upper leg ilc and a lower leg 99h, with the latter connected to and supported by a T member 2Q. A blank or plug i90 is disposed within the leg ich to prevent flow from the curved conduit lil to the l" member 2li. A short nipple 2li also connected in the "l eX tends through an opening 22 provided in one end `ol a liquid receiving and accumulating vessel 23 and said nipple is securely welded or otherwise secured to the vessel. Suitable braces which extend between the T and the vessel further secure the T firmly to the vessel.

An inclined pipe riti has its upper end connected to and in communication with the lower leg l9b of the curved conduit i9 in advance of the plug E30 (Figure 5) while its lower end is connected with the opposite end of the liquid-accuxnulating vessel Z3, With this arrangement it will be obvious that liquid separated in the horizontal separating chamber il may iiow downwardly through the conductor it, then through the curved conduit lil and then through the inclined pipe to the interior ci the vessel The T 2li by which the end of curved conduit I Sl is supported is also connected with a second curved conduit 2t which includes an upper leg 28a and a lower leg 26h. The here of the lower leg communicates with the T E while the upper leg has connection with the 'l' member i5 provided in the oilset portion of the main ilow line. The upper leg 2te of the conduit 2t is in the saine horizontal plane as the upper leg [9a of the conduit la and the legs Zlio and Hic also lie in the same horizontal plane as the lateral portion islb oi the conductor i8, as well as the lateral section ill of the offset portion in the flow line.

As has been noted the iiow stream may contain hydrocarbon liquid and also free water, and these liquids are separated by the separator l l and are conducted downwardly through the conductor i8 and inclined pipe 25 to the interior of the vessel Within the interior of the vessel the free Water, being heavier than the hydrocarbon liquid, will settle to the bottom while the hydrocarbon liquid will rise toward the top of the vessel. Because the curved conduit fill is in direct communication with the interior of the vessel 23 it will be 'ei-'ident that the hydrocarbon liquid will rise upwardly within this conduit and will enter the upper leg Ella, of the conduit. The gas which has been separated in the separator il is, of course, flowing downwardly through the oiset portion oi the flow line, which oiset, as has been explained, is formed by the down pipe lil, lateral Hl and upstanding pipe it. As the makes its turn through the T iii and ilows upwardly in the upstanding pipe i6, any liquid in lateral ifi is swept up with the gas so that the flowing gas functions to draw the liquid back into the now line. In actual practice, the level of the hydrocarbon liquid will be at the point L (Figure 5) in the conductor and in the lateral leg 26a because at any time that the level rises abcwe this point the owing gas will function to draw the liquid into the main flow line. The arrangement of the conductor lil and conduit S26 with respect to the vessel 23 thus provides inea-ns whereby the hydrocarbon liquids which are separated. in the separator il are brought ltends downwardly within the vessel 23.

back into the main flow line Without the necessity of forming any restriction or pressure drop in said line. Further, the arrangement of these conductors provides for an accurate control of the hydrocarbon liquid level, with the result that any variation in the weight of the liquid accumulating vessel 23 will be the result of a variation `of the level of the water within the lower end of said vessel.

The vessel 23 comprises a cylindrical shell having its ends closed by end members 2'I which are welded or otherwise permanently secured in place to withstand extremely high pressure. rlhe T 20 to which the curved conduits I3 and 26 are attached is welded or otherwise rigidly secured to one end o the vessel 23 and conductors I8 and I4 together with the conduits I9 and 26 form the sole support for the vessel. It may therefore be said that the vessel is in fact suspended from the main ilow line with the separator II forming a part of said line. For supporting the separator and the main flow line, a suitable frame 28 may be provided and such frame has the separator II rigidly fastened thereto. Any expansion or contraction of the supporting frame 28 which may be caused by atmospheric temperature variations will effect the main now line and since the vessel 23 is carried or suspended from the line the relative position of the vessel with respect to its supporting conductors will remain the same. Also, any variations in the main line will not cause a change in the relative position of the vessel with respect to the line. To assure rigidity of the offset portion of the ow line formed by the members I3, I4 and I6, the supporting frame 23 may be welded or otherwise secured by a brace 29 to the turn I'I which connects the offset portion to the pipe Illa of the main flow line.

By mounting the vessel 23 in the manner illustrated and by controlling the level of the hydrocarbon liquid, it is apparent that any change in the weight of the vessel 23 will be a result of a change in the level W of the water within said vessel. If the volume of water within the vessel increases to raise the water level W it will be evident that the overall weight of the vessel 23 will be increased. Such increase in weight will tend to deflect the vessel and its rigid supporting structure downwardly, and the tendency toward downward deflection will be greatest at the free end of the vessel, that is, at the end opposite the point of attachment of the supporting T 20. When a predetermined water level W occurs within the vessel it is desirable to discharge some of the water and for this purpose a discharge valve 36 (Figure 2) is provided. This discharge valve is illustrated as a motor valve and has connection through an angular line 3| with a withdrawal pipe 32 which ex- A suitable hand valve 33 may be connected in the line 3l to permit manual withdrawal of water from the Vessel, provided, of course, that the discharge Valve 30 is open. A suitable discharge line 34 extends from 'the valve 30 and it will be evident that when the valve is opened water from the lower end of the vessel may be withdrawn through said discharge line.

It is apparent that the discharge or dump valve 33 is to be opened when the water level within the vessel rises to a predetermined height and said valve must be closed when the water level has been lowered a predetermined amount. Closing of the valve occurs before all of the water is removed from the vessel in` order to prevent the escape of any of the hydrocarbon liquids which accumulate in the vessel above the water therein. In the present apparatus the deilection of the supporting structure of the vessel is utilized to control the operation of the discharge valve and manifestly this deflection will be in direct proportion to the volume of water which accumulates within said vessel. The weight of the water accumulating in the vessel will cause a downward deilection of the supporting structure with a, resultant movement of the vessel which will tend to move the outer free end of said vessel in a downward direction. This tendency of the outer free end of the vessel to :move in a downward direction upon increase of the weight will represent a downward force which, as will be explained, is utilized to control operation of the discharge or dump valve 30. Operation of the motor valve 3l) is effected by means of a pilot pressure fluid and as illustrated. the source of this pilot pressure fluid may be the high pressure main ow line IFJ. A portion of the high pressure gas owing through said line is conducted from the lateral leg I4 of the oilset portion of said line through a regulator A which functions to reduce the high pressure gas to a desired lower pressure. A pilot pressure fluid line 35 extends from the regulator A to a drip pot 36; from the drip pot the pressure is conducted through an ordinary regulator 31 which accurately controls the pressure of the pilot uid and then through a line 38 to a control unit B. The control unit is mounted on a supporting plate which overlies the free end of the vessel 23 (Figure 3) and the supporting plate is secured to the oset portion of the main ow line, being welded or otherwise rigidly fastened to the lateral I 4 of said offset portion. It will be evident that since the supporting plate 39 which carries the control unit B is fastened to the ilow line any movement of said line due to expansion and contraction will not change the relative position of the control unit B with respect to the vessel because both the unit and the vessel are carried or supported by the line.

The pilot control unit B has an operating stem lll at its upper end which is arranged to be engaged vby an adjustable screw 40a mounted in a transversely extending bar 4I which is carried by a supporting angle member 42, said bar being located in overlying relationship to the unit B. The pilot pressure fluid from the line 38 passes through the pilot control unit B and is then. conducted through a line 44 to the motor valve 30. It is thus obvious that the pil-ot control unit actually controls the application of pilot duid pressure to the motor operated discharge or dump valve 3i) whereby said discharge valve is opened and closed. The provision of the adjustable screw Mld permits an adjustment of the screw its bar lli relative to the stem whereby a control of the liquid level in the vessel may be had.

By observing Figure 3 it will be apparent that the vessel 23 is suspended at one end from the conductor I3 and the oiset portion of the main flow line whereby `the free end of the vessel will have a tendency to deflect downwardly upon an increase in weight of the vessel and will tend to return to a norrnal upward position upon a decrease in such weight. Through the angle member 42, bar li and screw 46u, a portion of the weight of the vessel is imposed upon the operating stem 40 of the control unit B and thus the force which is applied to the operating stern of the control unit is variable in accordance with. the weight of the vessel 23 and its contents. As will be explained, a predetermined application of force to the operating stern will result in building up a pressure within the pilot control unit B and upon reaching a predetermined pilot pressure the control unit B operates to apply full pilot pressure to the diaphragm of the mot-or valve, whereby said valve is opened to discharge Water from the vessel. Similarly, as water discharges through the open valve the weight of the vessel is reduced and the force applied to the operating stern il@ oi the control unit is accordingly reduced, whereby the control unit functions to shut the application of pressure to the motor valve diaphragm and to release the pressure acting thereon to cause said motor valve to immediately close.

From the foregoing it will be seen that the water permitted to accumulate in the vessel or tank 23 until a suiicient force has been applied to the operating stern lil of the control unit to build up a predetermined pilot pressure in said unit. When such predetermined pressure, which is representative of liquid level, is reached, full pilot pr scure is directed through the line till to the motor valve to operate the same with a snap action; similarly, when the iorce applied to the operating stern lil is decreased to a certain point, pressure to the motor valve is shut orf and is released to allow the motor valve to close with a snap action. It is pointed out that the actual movement of the vessel 23 is very slight and in actual operation as the vessel tends to rnove downwardly due to increased weight, the control unit functions to balance the applied force to substantially retain the vessel. in its initial position. This action of the pilot control unit, as will be explained, increases pilot pressure but the net resultant motion of the vessel 23 is zero. As additional force is applied to the operating stein due to increased weight on the vessel the operation is repeated, that is, the control unit B balances the applied force to further increase pilot pressure. In this manner, the vessel undergoes substantially no motion and it is therefore possible to mount said vessel rigidly by means of welded or other permanent connections to assure efcient operation, without leakage or friction under extremely high pressures.

in order to dampen the movement of the free end oi the vessel so as to prevent chattering a dashpot i3 (Figure l.) is mounted on the supporting plate and has its operating rod el en- `the under side of the bar el which is attached to the supporting angle member lli?. The dashpot prevents harmonic vibration of the free end of the vessel A suitable gauge glass d8 is connected with a pipe "l extending from the upper portion of the vessel and also with a pipe E@ connected to the lower end of the vessel. The pipe Il@ is below the liquid level within the vessel. An additional discharge line l connects with the pipe lill and has a suitable hand valve 52 mounted therein whereby an auxiliary manual discharge of the contents of the vessel may be had.

The various elements, such as the regulator, A, the pilot control unit B and the motor valve Sil are subject to some variation in construction since various types of these particular devices could be employed. The pilot control unit B must, however, be constructed so as to be extremely sensitive to a very small deflections of the 8 Vessel or tank 23. The preferred form of units which are employed are illustrated in Figures 6 to 8 and each unit will be briey described.

Referring to Figure 8, the regulator A is shown. As has been stated the particular regulator A maires it possible to employ the high pressure flow line lll as the source of the pilot pressure iluid. It is to be remembered that the gas within the line i@ is of relatively high pressure, probably of the order of 200i) pounds per square inch or higher. To reduce a portion of this fluid to a relatively low pilot pressure in the order of pounds presents a freezing problem and the regulator A is especially designed to allow a portion of the extremely high pressure ilow stream to be taken therefrom and its pressure reduced without danger or freezing. Where an outside source of low pressure pilot gas is available the regulator A may be omitted, but in most instances, such a source of low pressure gas is not readily obtainable and the regulator A permits the pilot gas to be taken from the high pressure line ifi.

The regulator includes body portion 53 which may be constructed of various sections with internal chamber :ifi being formed within body. An operating diaphragm 55 closes the upper end the chamber and an adjustable coil spring exerts a predetermined pressure on the diaphragm. The diaphragm has a depending "ianged stein il' connected thereto and this stem is connected through. an ordinary reverse motion assembly 5E! with Valve control rod 59. The lower end of the rod engages a ball valve Si! to urge the same into engagement with a seat El at the upper end of a restricted orifice 62. The valve tf its seat el are disposed Within an outer casing which is located wholly or entireiy within the flow stream passing through the lateral leg ifi or the oiset portion of the main iiow line ld.

It vwill be evident that when the pilot valve Ell is opened, the pressure reduction is at the seat iii and this is the point where normal freezing might occur. However, because or the location of the valve and the fact that only a very small volume of gas is taken frein the main gas stream the temperature of the'large volume of the main gaseous stream is suiicient to overcome o1' counteract the cooling effect whereby no freezing occurs. The pilot line has one end connected with the chamber and so long as the pressure within said Chamb r is at the desired pressure as determined by the adjustment of the spring 5t the diaphragm iid held in its upper position which through the reversing mechanism applies a downward force to the operating rod 59 and holds the valve Any reduction in pressure in the ci einher permits the spring 56 to urge the diaphragm downwardly and through the reversing mechanism 5S reduce the applied force on the rod 59, whereby the pilot valve lili be unseateo. to admit additional pressure into the chamber Eil. Upon this pressure again building up to a predetermined point the valve is again seated.

As has been pointed out the particular regulator A maires it possible to employ the high pressure fluid as the source of the pilot pressure fluid without danger of freesi g cr" the regulator and this eliminates the necessity of providing a separate source of pilot pressure fluid. It might be noted that the regulator shown in Figure 8 is fully described and claimed in my 3o-pending application, Serial No. 37,183, filed July 6.,' 194;.

accaaas The pilot pressure fluid is conducted from the regulator A through the line 35, drip pot 36, regulator 31 and line 38 to the pilot control unit B which is clearly shown in Figure 6. The ordinary regulator' 31 merely functions to steady and further reduce the pressure iiowing to the control unit, if such further pressure reduction is required. The control unit B is in effect a combined control and snap action device and comprises an upper casing section 64 having an inlet opening 65 at one side thereof, said opening having the pilot pressure line 38 connected thereto. The opening 65 communicates with a chamber 69 located axially within the lower portion of the casing or housing 84. An axial bore 61 extends upwardly from the chamber 59 and has a valve seat member 99 provided with an axial valve seat 69 threaded therein. The member 68 is formed with an axial bore 18 extending therethrough whereby flow from the pilot supply line 38 may enter the chamber 59 and then ilow upwardly past the valve seat 99 into the chamber 1I in the upper portion of the bore 61 of the casing. A valve 12 is adaptec'l to engage the seat 69 and has a valve stem 19 projecting upwardly therefrom; the upper end of the valve stem is threaded into the depending shank 19 of a tubular element 15. -A diaphragm 18 spans the upper end` of the bore 61 of the casing and the outer periphery thereof is clamped between the upper end of the casing and a locking ring 11. The diaphragm 18 has a central opening through which the shank 14 extends and a clamping nut 18 clamps the under side of the diaphragm to the element.

The operating stein 139 of the unit B is hollowed out and has its lower edge engaging the upper edge of the tubular element 'i5 which carries the valve 12. The interior of the stem or operating member 49 and the enlarged upper portion of the bore of the tubular element form a chamber 19 which has communication with the area below the diaphragm 19 through a vertically extending passage 90. The stem or operating member 48 is flanged and may undergo limited upward movement with respect to the tubular element 15 but is coniined against complete upward displacement by a retaining cap 8i which is threaded onto the upper end of the casing 64. The area of the chamber 1I below the` diaphragm but above the valve seat communicatesthrough an inclined passage 82 with an opening 83 formed in thecasing. A U-shaped conductor ibi has its upper end threaded into the opening 99 and will function to conduct pressure fluid from the chamber 1 I.

An intermediate section or body 85 is secured to the lower end of the casing 54 and a base section 86 is fastened to the lower end of the intermediate body. The body 85 has an axial bore 81 which is enlarged at its lower end to form a chamber 88. A valve assembly is mounted within the intermediate section and comprises an upper valve disc 89 having an annular valve seating ring 99 and a lower valve disc SI having an annular valve seating ring 92, the discs being connected by a shank 93 which extends through the bore 81. The upper valve 89 is disposed in the chamber 66 in the lower portion of the casing 64 and has its valve ring adapted to engage a flexible seat 94 provided on the upper end of the intermediate body 95. The lower valve has its valve ring 92 adapted to engage a flexible seat 95 provided at the intersection of the bore 81 and the chamber 88.

A diaphragm 96 closes the lower end of the" chamber 88 and is confined between the body 85 and the base 86. The central portion of the base is formed with a chamber 91 below the diaphragm 96 and an inlet port 98 communicates with the chamber. The conductor 84 which leads from the chamber 1I in the upper casing 64 has its lower end connected in the port 98 so that 'the pressure fluid from chamber 1I may be conducted to the chamber 91 below the diaphragm 95. Opposite the inlet port 98 the base is formed with an outlet 99 which is normally closed by a plug im). As will be pointed out this opening may be utilized when it is desired to actuate the motor valve with a throttling action but where snap action is required, the plug closes said opening.

The intermediate body or section 85 is formed with a radial outlet port I8I which has the pressure line 44 connected thereto. Extending through the wall of the body and from the chamber 88 is a bleed or relief port |92 and when the valve discs are in a lowered position, as shown in Figure 6, pressure .duid within the line 44 may be relieved through the bore 81, chamber 38 and relief port 1192.

The diameter or area of the valve 90 at .its seating position is of greater cross-sectional area than the diameter of the valve 92 at its point of seating and the length of the connecting shank 93 is such that when one of the valves is seated the other is unseated. The lower end of the chamber 88 is, of course, closed by the flexible r diaphragm 96 and the effective cross-sectional area of said diaphragm is greater than the effective seating area of the upper Valve 90. The diaphragm 96 actually functions as the top of the chamber 91 in the base 86 and is, therefore, exposed to the pressure within said chamber.

With the motor valve 30 to be operated with a snap action the plug H89 closes the port 99 in the base and the line 44 is connected in the port IUI of the unit B. The constant supply pilot pressure from line 98 is present within the chamber 66 and is acting on the effective cross-sectional area of the upper valve 98 to hold this valve downwardly in a seated position. As the force applied on the operating member or stem 48 of the unit is increased due to an increase in weight of the vessel 23, the valve 12 is moved toward an open position and the pilot pressure is permitted to ow into the chamber 1I. Immediately that the pressure enters the chamber 1I it acts upon the diaphragm 16 to immediately balance the applied force and return the operating stern to its initial position with the valve 12 closed. Thus, a certain pressure is present in the chamber 1I but this pressure is less lthan the full pilot pressure. As additional liquid accumulates in the vessel 23 and an increased force is again applied to the stem 49 the Valve 'I2 is again momentarily opened and additional pressure is admitted to chamber 1l. This pressure is present within passage 82 and conductor 84 and within the bore 81 below the diaphragm 96. Obviously, until such time as the pressure within chamber 1I and the chamber 91 reaches a predetermined point the full pilot pressure which is acting on the upper valve 89 will hold said valve in a seated position. The relationship between the cross-sectional area of the diaphragm 96 to the valve 99 will control the point to which the pressure must be built up in chamber 91 before the valve discs 89 and 9| are moved upwardly.

It will be evident that through the valve 12 the pressure in chambers 1I and 91 is modulated or controlled in accordance with the force being applied to the operating vstem to and when this pressure has built up to the predetermined point for which the device is constructed the pressure in chamber 91 is sufficient to inov'e the valve discs upwardly; at this point unseating of the valve 9B will admit full pilot pressure to the bore 8'1` and to the line 4d leading to the motor v'alve. Thus, full pilot pressure is applied to the motor valve to open the same with a snap action. At the instant that the pressure in the chamber lll a'cting against the diaphragm 96 overcomes the constant supply pressure acting to hold the valve discs downwardly both valve discs are snapped upwardly and the action is so rapid due to the sudden release of force holding the valve assembly down that the lower valve e2 moves into engagement with its seat 9E before the pilot 'pressure can I'ill the volume of the bore 8l between the upper and lower valve discs. As has been noted, the area of the valve S2 is less than the area of the valve 90 and thus, the pilot supply pressure which is tending to move the valve downwardly oir of its seat is acting on the lesser area of the valve 92. Because the 'elective area o f the diaphragm Se is considerably larger than the area of the lower valve said lower valve will be held seated against the full pilot pressure and the motor operated discharge valve Si) is thus snapped t an open position. y

When the valve opens and liquid is' conducted lfrom the vessel a reduction in the applied for-ce to the pilot operating member occurs and as this force reduces sufficiently the pressure in the Chamber ll formed between the operating stern 40 and the tubular element l5 allows these parts to separate to permit venting of the pressures within the chambers 'il and 97. When this pressure in these chambers has reduced to a `point where the full pilot pressure acting on the lower valve 92 can unseat said valve, the lower valve begins to niove downwardly. As the lower valve 92 begins to leave its seat there is a momentary leakage of pilot gas past this seat outwardly from the relief port N32 and since the diameter of this opening is relatively small a back pressure is built up within the chamber '88 above the dia'- phragm Qt. This back pressure immediately ac't's on the top side of the diaphragm 96 and e'a'use's the diaphragm to remove all resistance yto the lowering of the valve disc assembly "and Ythe full pilot pressure in chamber Et then seats the upper valve. The pressure which `funotions to open the motor valve Sil may then bleed outwardly through the bore tl, chamber 8S and vent opening It?. The parts will remain 'in this position until the applied force again builds "up the nodulated pressure within the chambers 'H and 91 at which time the operation is repeated.

I'f it is desired to operate theJ ino'tor valve with a throttling action the line d'4 leading to said motor valve is connected within the por't '9'9 while the plug Hl closes the port I'l. In such c ase, it will be evident that the pressur in "the chambers H and 97 will control the positionof the motor valve. It might be noted that the unit B is a combined control and snap action 4unit and is fully disclosed in my cofpending application, Serial No. 105,203, nled July 1'6, 1949. t is not necessary that the snap 'action 'control be incorporated with the modulated pressure 'control since the snap action device could vbe a "separate unit. Y

The particular rnotor valve which is 'employed is, of course, subject to variation but as 4'illustrated includes rthe oper-ating ydi'aphr'agiirs 4'5 which has connection with a valve stern m3 having a valve element IM at its lower end. 4 A coil spring m5 resists movement of the diaphragm 45 and maintains the valve H84 in a closed position. When a pressure is applied beneath the diaphragm the Valve i013 is opened to permit lflow through the discharge line 34.

In the operation of the apparatus', the vessel I23 receives the separated liquids from the now line lll, such separation being effected by the separator Il. The liquids flow downwardly through the curved conduit I9 an@l inclined pipe 25 into the vessel. These liquids nray be water and hydrocarbon liquids and Obviously the water will settle to the lov/fer portion of the vessel.

The gas which will be separated in the separator I I ows downwardly through the offset portion formed by the down pipe I3, lateral 'M and upstanding pipe lll in the main now line, and then continues down the line through the main now pipe Illa. The upper portion of the vessel 23 is in communication with the oir-set portion 'of the main ilow line through the curved conduit 26 and thus the hydrocarbon liquids which rise above the water in the vessel may pass upwardly through the curved conduit. The upper end oi' the conduit 2S is disposed in the same plane as the lateral lil of the offset portion 'of the now line and upon the hydrocarbon liquids reaching this level a syphon 'effect is produced whereby the nowing 'gas strear'n functions to withdraw the hydrocarbon liquids back into the main line. In addition this construction provides for maintaining the level of the hydrocarbon liquids constant so that an'y `'variation in the weight of the vessel 23 will be due to a variation in water level W within said vessel.

The vessel is rigidly supported 'at one end so that as the weight thereof increases its free end tends to move downwardly. This 'free end .is applying a force to the control 'unit `B and as has been explained, as the vessel 23 tends to move `downu'rardl'y because of increased weight an increased force is applied to the operating' stein et of the 'control unit. Immediately that this force is appue the control 'unit is actuated to increase the modulated pressure and this pressure balances the applied force to maintain the vessel in substantially Vits initial position. Thus, the modulated pressure is increased in the chambers 71 and St 'of the control unit while the net resultant motion of "the vessel is zero.

` As the water level 'the vessel rises the applied force increases vand "the modulated .pressure tends to increase accordingly and when this pressure re'a'che's a predetermined point, .full pilot pressure is 'applied to 'the motor valve Bil to open 'said valve 'and discharge water. 'he `discharge of water Treni the vessel "reduces the overall -weight of said vessel and also reduces the applied force to 'the runit B. Decrease in applied force 'remlts 'in decrease of modulated pressure to the point 'where the .pressure acting on the motor "valve is relieved to close said motor valve Sil. It 'is 'thus obvious that the apparatus .providesra unit -v'vl'ierc-:in the weight of the liquid acfcu'rniilatin'g vessel 4is utilized to control the op.; eration of 'the vdischarge valve and this control is aeeonplished with substantially zero motion or the vessel. This means that the vessellrnay-be rigidly "mountedso that all .joints may .be .per-- manen'tly `vvelde`d` to withstand the excessively high pressures. Actually the entire vessel -funcL tions :as a Ifloat and therefore extremely sensitive operation is produced. o -inter-nal noa-t 13 mechanism with its inherent disadvantages is required.

Ihe apparatus provides an arrangement whereby the flowing gas stream is utilized to return the separated hydrocarbon liquids into the main flow line without the necessity of providing restrictions or chokes which create pressure drops in said main flow line. Also, the vessel and the control devices are all supported from the main flow lines with the result that any movement of the line due to expansion and contraction because of atmospheric temperature changes will not change the relative position of the control unit with respect to the vessel. With this arrangement an accurate and sensitive control is had because the only variation which occurs between the relative position of the vessel to the pilot control unit is due solely to a change in weight of the vessel and its contents. Although the separator has been illustrated as mounted adjacent the liquid accumulating vessel it is apparent that it could be located at some distance therefrom, in which case the conductors I3 and i4 would be extended to locate the separator I I at a distance from the liquid accumulating vessel.

From the foregoing it will be seen that this invention is one well adapted to attain all of the ends and objects hereinabove set forth together With other advantages which are obvious and are inherent to the structure.

It will be understood that certain features and subcomb-inations are of utility and may be employed without reference to other features and subcombinations. This is contemplated by and is within the scope of the claims.

As many possible embodiments may be made :of the invention without departing from the scope thereof, it is to be understood that all matter herein set forth or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense.

Having described the invention, I claim:

1. A liquid knockout apparatus for removing liquid from a high pressure fluid flow line including, a liquid-accumulating vessel communicating with and suspendedat a single point of support from the high pressure fluid line for receiving liquid which has been separated from the line, a discharge valve for controlling the discharge of liquid from said vessel, said vessel being supported in a normal position with the weight of the vessel and its contents unequally distributed on opposite sides of its point of support, a control unit also supported by the fluid line and engaged by the exterior of the vessel at a point spaced from the point of support of said vessel whereby a portion of the weight of the vessel is applied to said unit, and means in the control unit responsive to the force applied by the weight of the accumulating vessel for effecting a balance of such force, variations in the weight of said vessel and its contents due to changes in the weight of the liquid therein resulting in variations in the force applied to the control unit, and means for actuating the discharge valve of the vessel in accordance with the force applied to the control unit.

2. A liquid knockout apparatus as set forth in claim 1, together with means for returning a portion of the liquid from the vessel back into the now line.

3. A liquid knockout apparatus as set forth in claim l, wherein the discharge valve is pressureactuated, means for supplying an operating pres- 14 sure to said discharge valve, and means actuated by said control unit for controlling the application of pressure through the pressure supply means to the discharge valve, whereby operation of said discharge valve is actually controlled by the control unit.

4. A liquid knockout apparatus for removing liquid from a high pressure fluid now line in# cluding, a liquid-accumulating vessel communicating with the high pressure line for receivingliquid which has been separated from the line, a discharge valve for controlling the discharge of liquid from said vessel, means for attaching and suspending one end of the vessel t-o the flow line so that the iiow line supports a portion of the weight of the vessel, and its contents, a control unit engaged by the vessel at a point spa-ced from the point of attachment of the vessel with the flow line for also supporting a portion of the weight of the vessel and its contents, and a support for the control unit secured to the flow line,` whereby said control unit and vessel are carried by the iiow line, and means in the control unit responsive to changes in the force applied to the control unit by variations in weight of the vessel and its contents for controlling operation of the discharge valve.

5. A liquid knockout apparatus as set forth in claim 4 together with means for conducting a portion of the liquid which accumulates in the vessel back into the flow line.

6. A liquid knockout apparatus including, a high pressure flow line for conducting high pressure uid from a well,` means for mounting a liquid accumulating vessel in communication with the flow line in a position below said line for receiving liquids from said line, a discharge valve for controlling the discharge of liquid from the lower end of the vessel, means actuated by deflection of the mounting of .the vessel as caused by the weight of the vessel and its conte-nts for controlling the operation of the discharge valve, and a conductor having its lowerend communicating with the upper .portion of the vessel and having its upper end terminating in the same plane as and communicating with the iiow line, said ow line having a vertical portion adjacent the conductor, whereby when the liquid from the vessel rises upwardly in the conductor and said liquid enters the flow line,` the flowing uid stream in said line will carry said liquid upwardly in said vertical portion and then through the flow line beyond said vertical portion.

7. A liquid knockout apparatus for removing liquid from a high pressure fiuid fiow line wherein the fluid contains hydrocarbon liquid and water, said apparatus including a liquid-accumulating vessel communicating with` and suspended at a single point of support from the high pressure iiow line for receiving liquid which has been separated from the line, a pressure-actuated discharge valve for controlling :the discharge of liquid from said vessel, said vessel being supported in a normal position with the weight of the vessel and its contents unequally distributed on opposite sides of its point of support, a control unit also supported by the fiuid line and engaged by the exterior of the vessel at a point spaced from the :point of support of said vessel whereby a portion of the weight ofthe vessel is applied to said unit, means in the control unit responsive to the force applied by the weight of the accumulating vessel for effecting a balance of such force, variations in the weight of said vessel and its contents due to changes in the weight of the liquid therein resulting in variations in the force applied to the control unit, means for supplying an operating pressure to said pressure-actuated discharge valve, means operated by said control unit for controlling the application of pressure through 'the pressure supply means to the discharge valve, whereby operation of said discharge valve is actually controlled by the control unit, and a conductoi` establishing communication between the upper portion of the liquid-accumulating vessel and the ow line, whereby hydrocarbon liquid accumulated in the vessel will be returned to the iiow line.

8. A liquid knockout apparatus as set forth in claim 7, together with means utilizing the flowing iiuid stream in the flow line for drawing the hydrocarbon liquid which accumulates in the vessel baci: into the iiow line.

9. A liquid knockout apparatus including, a high pressure fluid flow line having a downwardly disposed offset portion therein, a closed liquidaccumulating vessel in a `,plane below the flow line, a conductor extending from a point upstream ,of the offset portion of the flow line to the vessel for conducting liquids separated from rthe iiow line to said vessel, a second conductor having its lower end communicating with the vessel and its upper end connected with the offset portion of the now line, whereby when the liquid level rises within the second conductor and en- ;ters said oilset portion the flowing iiuid stream within the flow line functions to draw said liquid back into said flow line, the two conductors forming the sole support for the liquid-accumulating vessel and being secured to the vessel at one end lthereof, whereby the opposite end of said vessel will undergo movement caused by the variations in weight of said vessel due to changes in quantity of liquids therein, a discharge valve for controlling the discharge of liquid from the lower portion of the vessel, and means actuated by the movement of the Vessel as caused by variations in weight of the vessel and its contents for operating said discharge valve.

10. A liquid knockout apparatus including, a` high pressure fluid flow line having a downwardly disposed offset portion therein, a closed liquidaccumulating vessel in a :plane below the ow line, a conductor extending from a point upstream of the offset portion of the dow line to the vessel for conducting liquids separated from the flow line :to said vessel, a second conductor having its lower end communicating with the vessel and its upper end connected with the offset portion of the new line, whereby when the liquid level rises within the second conductor and enters said offset portion the ilowing iuid stream within the iiow line functions to draw said liquid back into said flow line, the two conductors forming :the sole support for the liquid-accumulating vessel and being secured to the vessel at one end thereof, whereby the opposite end of said vessel will undergo movement caused by the variations in weight 0f said vessel due to changes in quantity of liquids therein, a discharge valve for controlling :the discharge of liquid from the lower portion of the vessel, a control unit engaged by the unsupported end of the vessel and responsive to weight changes in the vessel for operating the discharge valve, and a support for said control unit extending from. and secured to the fiow line.

il. A liquid knockout apparatus including, a high pressure flow line for conducting high pressure iiuid from a well, means for mounting a liquid accumulating Vessel in communication with the now line in a position below said line for receiving liquids from said line, a discharge valve for controlling the discharge of liquid from the lower end of the vessel, means actuated by deflection of the mounting of the vessel as caused by the weight oi' the vessel and its contents for controlling the operation of the discharge valve, and a conductor having its lower end communieating with the upper potrion oi the vessel and having its upper end terminating in the same plane as and communicating with the iiow line, said flow line having a vertical portion adjacent the conductor, whereby when the liquid from the vessel rises upwardly in the conductor and said liquid enters the fiow line, the `flowing iiuid stream in said line will carry said liquid upwardly in said vertical portion and then through the flow line beyond said vertical portion, said discharge valve being pressure-actuated, and means for supplying operating pressure to said discharge valve from the high pressure ow line.

ASBURY S. PARKS.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 897,161 Senter Aug. 25, 1908 1,274,486 Willis Aug. 6, 1918 1,315,662 Gouchenour Sept. 9, 1919 1,496,090 Marker et al June 3, 1924 1,529,162 Bruce Mar. 10, 1925 1,530,836 Kuzilik Mar. 2e, 1925 1,603,655 Willis et al. Gct. 19, 1926 1,633,858 Groves et al. June 28, 1927 1,886,686 Jackson Nov. 8, 1932 1,908,891 Coe May l5, 1933 2,224,345 Heathman et al. Dec. l0, 1940 2,235,332 Combs Mar. 25, 1941 2,423,793 Olivo et al July 8, 191i? 2,507,278 Schultz May 9, 1950 

